Function sReadBMP

Engine/source/gfx/bitmap/loaders/bitmapBmp.cpp:93–169

//

static bool sReadBMP(Stream &stream, GBitmap *bitmap)
{
   PROFILE_SCOPE(sReadBMP);
   BITMAPINFOHEADER  bi;
   BITMAPFILEHEADER  bf;
   RGBQUAD           rgb[256];

   stream.read(&bf.bfType);
   stream.read(&bf.bfSize);
   stream.read(&bf.bfReserved1);
   stream.read(&bf.bfReserved2);
   stream.read(&bf.bfOffBits);

   stream.read(&bi.biSize);
   stream.read(&bi.biWidth);
   stream.read(&bi.biHeight);
   stream.read(&bi.biPlanes);
   stream.read(&bi.biBitCount);
   stream.read(&bi.biCompression);
   stream.read(&bi.biSizeImage);
   stream.read(&bi.biXPelsPerMeter);
   stream.read(&bi.biYPelsPerMeter);
   stream.read(&bi.biClrUsed);
   stream.read(&bi.biClrImportant);

   GFXFormat fmt = GFXFormatR8G8B8;
   if(bi.biBitCount == 8)
   {
      // read in texture palette
      if(!bi.biClrUsed)
         bi.biClrUsed = 256;
      stream.read(sizeof(RGBQUAD) * bi.biClrUsed, rgb);
   }
   bitmap->allocateBitmap(bi.biWidth, bi.biHeight, false, fmt);
   U32   width  = bitmap->getWidth();
   U32   height = bitmap->getHeight();
   U32   bytesPerPixel = bitmap->getBytesPerPixel();

   for(U32 i = 0; i < bi.biHeight; i++)
   {
      U8 *rowDest = bitmap->getAddress(0, height - i - 1);
      if (bi.biBitCount == 8)
      {
         // use palette...don't worry about being slow
         for (S32 j=0; j<width; j++)
         {
            U8 palIdx;
            stream.read(&palIdx);
            U8 * pixelLocation = &rowDest[j*bytesPerPixel];
            pixelLocation[0] = rgb[palIdx].rgbRed;
            pixelLocation[1] = rgb[palIdx].rgbGreen;
            pixelLocation[2] = rgb[palIdx].rgbBlue;
            if (bytesPerPixel==3)
               pixelLocation[3] = 255;
         }
      }
      else
         stream.read(bytesPerPixel * width, rowDest);